1. Field of the Invention
This invention relates to fibrous articles intended for absorption of body fluids and, in particular, to tampons and similar catamenial devices. Such fibrous articles may include a plurality of crystalline siliceous molecular sieve materials for the purpose of suppression or removal of menstrual odors.
Fibrous absorbent articles have been known for some time. They incorporate a plurality of fibers arranged in a structure to absorb and retain body fluids. In connection with the present invention, the body fluid of particular concern is menstrual fluid which may generate unpleasant odors.
A variety of proposals have been made in the past as a means to counteract menstrual odors. Such proposals have included the use of perfumes to mask the odors that emanate from the absorbent article. Other proposals include the use of substances to suppress or remove odoriferous compounds that may be generated in the presence of menstrual fluids and the like. These odoriferous compounds may be suppressed by a number of mechanisms including forming a non-odoriferous compound by chemical reaction or by adsorption of the odoriferous compounds into a solid or liquid. For an adsorbent to be effective in deodorizing, especially for odors from body fluids that are characterized as having very low olfactory thresholds, it is essential that the sorbent be capable of removing, in its environment, virtually all the odoriferous compounds regardless of the concentration thereof.
2. Description of the Prior Art
In order to provide a full background for the present invention reference may be made to U.S. Pat. Nos. 3,948,257; 4,795,482; 4,826,497; and 5,364,380; also Registration HI579.
U.S. Pat. No. 3,948,257 is directed to a vulva deodorant system comprising a tampon for insertion into the vagina and a device for retaining a deodorant. The device may include a deodorant in the form of a perfume, powder or the like.
U.S. Pat. No. 4,795,482 is directed to a process for eliminating organic odors and compositions for use therein. The method involves reducing the odors below olfactory detection by contact of the odor producing species with a synthetic crystalline siliceous molecular sieve material.
U.S. Pat. No. 4,826,497 provides fibrous absorption articles having enhanced deodorizing properties by having disposed therein an effective amount of crystalline siliceous molecular sieve having pore diameters of at least about 5.5 Angstroms and a relatively low capacity for adsorbed water. In addition, this patent provides for the inclusion of zeolite particles having a size of less than about 20 micrometers in the deodorizing sieve. The particles are positioned between the exterior surface of the fluid permeable cover of the absorbent article and a baffle provided within the article.
U.S. Pat. No. 5,364,380 provides an absorbent article having a first surface facing the body of a user and a second surface aligned approximately opposite to the first surface. There is also provided a liquid-impermeable baffle and a fluid-permeable cover positioned adjacent to the respective surfaces. In addition, a deodorizing mixture is positioned within the article so as to remain dry for a substantial period of time. The mixture is an anhydrous, non-buffer blend of at least basic and pH neutral odor adsorbing particles.
Registration HI579 provides zeolites having xe2x80x9cintermediatexe2x80x9d SiO2/Al2O3 ratios used in catamenials, diapers and the like to control odors. Such intermediate ratios are described as typically in the range from about 2 to about 10.
It may be the case that when applied appropriately there are particular benefits and advantages to the several inventions described in the aforesaid patents. However, it will be apparent that the present invention provides a key advantage not found in prior art. What has been discovered and recognized is that specific natural zeolites have unique capabilities in that they have the property of controlling and suppressing odor in the presence of moisture. Consequently, a very effective and efficacious fibrous absorbent article, for example, a tampon, can be fabricated in such a way as to capitalize on the natural zeolite""s capability for adsorbing odoriferous organic molecules associated with menstrual fluids even in the presence of water that may be present in such fluids.
One of these specific zeolites can be classified as a thermal type 3 clinoptilolite species based on its chemistry and silica/alumina ratio. The zeolite, clinoptilolite, has been discussed in the book entitled Natural Zeolites by O. Gattardi and E. Gall; published by Springer-Verlay, 1985. This thermal behavior, type 3 zeolite is defined as a zeolite capable of undergoing continuous reversible dehydration with only very small lattice contraction, and the lattice is not destroyed so long as temperature remains below 750xc2x0 C. This zeolite is an off-white clinoptilolite with potassium as the primary exchangeable cation. The presence of this exchangeable cation is believed to be the main influencing factor on the thermal behavior, as set forth in the article cited.
Another zeolite that has been shown to be efficacious is chabasite. This zeolite is a tan mineral with sodium as the primary exchangeable cation. The odor adsorbent efficacy of this zeolite is likely due to its very high surface area (500 m2/gm), the sub micron size (0.2xcexc) of the individual crystalline structures, and its large pore size. These features combine to provide a more readily accessible lattice resulting in a more rapid rate of odor adsorption.
Accordingly, it is an object of the present invention to provide a catamenial device or product, such as a tampon, that can be reliably and inexpensively produced and that will efficiently adsorb odors associated with menstrual fluid.
It is another object of the present invention to maximize the effect of a desired amount of odor adsorbent material in a tampon.
It is further object of the present invention to provide the tampon with efficient odor adsorption even in the presence of water or other liquid.
It is a still further object of the present invention to provide a method of incorporating the odor adsorbent material into a tampon.
The above and other objects of the present invention are fulfilled by the feature of a tampon or similar device or product in which there is disposed a natural zeolite of the specific type. Briefly stated, a broad feature of the present invention can be defined as follows: a fibrous absorbent article for absorbing body fluids made up of a fibrous material defining a structure suitable for absorbing the body fluids, and disposed within the structure an effective amount, so as to reduce odors from the body fluids, of a molecular sieve constituted of a natural zeolite of the clinoptilolite or chabasite species comprising SiO2 and Al2O3.